For radio receivers, circuits to process audio signals are generally known. These circuits enable tone control, particularly of the frequency response for high and low frequencies, volume control, and for stereo reproduction, balance adjustments. For reproduction with more than two loudspeakers, an adjustment of the volume relationship between the individual groups of speakers, such as between the front and back speakers in a car, is likewise known. There are various advantages to the use of digital circuits for such tasks, like good reproducibility of the settings, simple realizability with integrated circuits and the end to calibration due to variances in production.
In processing digital audio signals, the number of quantization stages is a significant factor. Often a 16 bit quantization of the audio signals at the analog/digital conversion is carried out. This is perceived adequate for obtaining reasonably low quantization noise, even st the high dynamics of musical performances. However, this is only true, if the amplitude range to be quantized is completely utilized.